Process for producing a slub yarn

ABSTRACT

A process for producing slubs onto a multifilament yarn which comprises feeding the yarn into a hood receiving a jet of compressed gas and withdrawing the yarn through a hole of the hood from the deflected stream of the gas at lower rate than the feed rate.

United States Pate Inventors Appi. No. Filed Patented Assignee Priority Shim Fniita Tokyo;

Jusuke Ushiki, isezaki-shi; Nageo Nkhizawa, Matsndmshi; Seiji Okewa, Wmbi-sld; Kunio Sekiye, Matsudo-shi; Hiroshi Kadnwnki, Matsudo-shi, all oi, Japan June 23, 1969 July 13, 1971 Nippon Rayon Co. Ltd.

Tonouehi Uji-Uji-shi, Japan June 27, 1968,1111 27, 11968 43144691 and 43/44692 PROCESS FORTPRODUCING A SLUR YARN 7 Claims, 13 Drawing Figs.

[51] lnt.Cl D02g 1/16, D02g 3/34 50 Field of Search 57/34 B, 157 F, 140 J, 91; 28/14, 72.12

[56] References Cited UNITED STATES PATENTS 3,118,269 1/1964 Biisky 57/34 3,262,177 7/1966 Cobb et a1. 28/1.4 3,296,785 1/1967 Hardy 57/34 3,433,007 3/1969 Myers 28/1.4 XR 3,517,498 6/1970 Burellier et al.

Primary Examiner-John Petrakes Attorney-Pierce, Scheffler & Parker ABSTRACT: A process for producing slubs onto a multifilament yam which comprises feeding the yarn into a hood receiving a jet of compressed gas and withdrawing the yarn through a hole of the hood frorn the deflected stream of the gas at lower rate than the feed rate.

PATENIEU JUL 1 319?| sum 1 BF 8 PATENIED JUL] 3191:

' snmanF a v PATENTED JUL 1 a l97| PATENIEI] Jun 3191! SHEET 8 OF 8 PATENTED JULI 3191: 3.591; 955

SHEET 8 BF 8 PROCESS FOR PRODUCING A SLUB YARN BACKGROUND OF THE INVENTION It has long been known that a multifilament yarn can be slubbed by passing through a high-velocity stream of compressive fluid. In the presently known process a jet of fluid is used to introduce coils, loops and folds along the filaments forming the yarn. In any one of these process, the jet is not effectively and economically used but has been required to provide otherwise a slub jet for a sole purpose of forming the slubs. This imposes a high-consumption of the compressive fluid and high maintenance costs upon the operation, rendering the products very expensive.

The present invention is directed to eliminate the conventional slub jet by substituting deflected flow of the supply jet for the slub jet. After extensive investigation, we have found a novel method involving a hood which enables the supply jet to serve also as a slubbing jet after it is deflected at the apex of the hood.

It is the object of the present invention to provide a novel method for producing a multifilament slub yarn, according to a simple process which avoids the necessity of a slub jet.

Another object of the present invention is to provide a slub yarn in which slubs are tightly formed by continuous filaments at irregular intervals in its length.

SUMMARY OF THE INVENTION According to the invention, there is provided a process for producing a slub yarn characterized by:

a. jetting a compressive gas into a hood having a hole at the apex thereof to deflect at the apex and to escape backwardly,

b. feeding a multifilament yarn in the deflected stream of gas to fold back the filaments composing the yarn on themselves at the apex of the hood, and

c. withdrawing the yarn from the deflected stream of gas through the hole of the hood, at a rate at least 0.5 percent less than the rate of feed, so that the yarn passes through the deflected stream of gas in a countercurrent direction to form slubs composed of filament loops consolidated into the yarn by filament entanglement.

BRIEF DESCRIPTION OF THE DRAWING FIG. I schematically shows a preferred embodiment of the apparatus for carrying out the process according to the present invention.

FIG. 2 shows a perspective view of the hood in FIG. I partially cut away to illustrate its inner configuration and slubbing.

FIG. 3 schematically shows another type of apparatus for carrying out the process according to the invention.

FIG. 4 shows a cross-sectional view taken along IV-IV line of FIG. 9.

FIGS. 5 to 8 show schematically broken, side views greatly enlarged of slub yarns which can be produced in accordance with the invention.

FIG. 9 shows schematically another type of the apparatus for carrying out the process according to the invention.

FIG. 10 and FIG. II schematically and partially shown broken, perspective views of the hoods.

FIG. 12 schematically shows an embodiment of the moving means.

FIG. 13 schematically shows main parts of a jet loom used for weaving the slub yarn.

DESCRIPTION OF THE PREFERRED EMBODIMENTS referring to FIG. I there is shown a preferred embodiment of the apparatus for carrying out the process according to the invention.

The multifilament yarn l is withdrawn from-a letoff package 2 through pigtail guide 3 and tension disc 4, by a pair of feed rolls 5 and 6, the yarn passing a sufficient number of times around the pair of rolls to provide positive control of the feed rate. The yarn then enters into nozzle 7 through its hole 8 and advances toward the dome-shaped apex of hood 9 with a highvelocity stream of gas introduced into the rear end of the nozzle by pipe 10. The stream of gas flowing along one side of the hood due to the fact that the longitudinal axis of the straight nozzle 7 is offset from the longitudinal axis of the hood on which the yarn withdrawal hole 16 is located is deflected along the concave surface of the apex and escapes backwardly. After deflection, the stream of gas serves to slub the yarn passing in countercurrent direction.

The yarn is then dashed against the apex of the hood by the stream and the excess length of overfeed is then folded back on the subsequently continuing portion of the yarn by the deflection of the stream. It will be understood that a certain continuance of this state might eventually allow time for forming a slub with each filament in entanglement. The slub thus produced is then withdrawn through the hole 16 at the apex by withdrawal rolls 11 and 12 similar to feed rolls 5 and 6, but operated at lower speed. The yarn passes after leaving the withdrawal rolls to a conventional windup, such as a package 13 surface driven by a takeup roll 14 through traverse guide 15.

In FIG. 2, the hood is shown in greatly enlarged state. The filaments are folded back on themselves by the defected stream of gas. Although both feed and withdrawal are kept at constant speed during the operation, formation of slubs arises intermittently. As a result of this the portion of the yarn between the feed roll and withdrawal roll is subjected to a fluctuation of tension during the operation. The excess length of the overfeed should be controlled in a range that the overfeed is quite sufficient to insure in the yarn always necessary folds of filaments to, produce the slub, but under all circumstances opposes a minimum obstruction to a stoppage of advancement into which an extremely excess feeding will fall.

Referring to FIG. 3, there is combined a fluid false twister 17 with the apparatus as described above. The other parts except the false twister are similar to corresponding parts of the apparatus of FIG. I. The fluid false twister has fluid conduits I8 and I9, entering a cylindrical yarn passage way 20 from opposite sides as shown in FIG. 4. The fluid conduits I8 and 19 are secured to the body in tangential relationship with respect to the section of the yarn passageway, whereby a vortex stream exerted along the direction of the arrow introduces an alternate twist in the yarn. An enlarged illustration of the slub produced by the practice of the invention is shown in from FIG. 5 to FIG. 8. A state ofthe slub immediately after leaving the hood is seen in FIG. 5, which varies to a state of FIG. 6 by passing through the fluid false twister 17. It will be seen that the left side portion of the slub has an S twist, hile the right side portion has a Z twist.

Referring to FIGS. 10 and 11, there are shown two types of the hole of the hood. The hole 16' of FIG. l0.has a recess closely neighboring with the hole which recess increases its depth to an increasing degree of approach to the hole. This serves to control the direction of the deflected stream and formation of slub is attained in a somewhat greater complication of loops of the filament than is formed by the hood having the hole 16 as shown in FIG. 11.

In FIG. 9, there is provided a yarn-scrubbing device 21 in which three poles 22 are secured on a body 23 in parallel with each other and two separaters 24 are secured in contact with two neighboring poles. The yarn passes through a reverse curve formed by the poles in frictional contact with the poles under urging of the withdrawal rolls. By passing through the device, the slubs are leaned in adverse direction against the advancement of the yarn as shown in FIG. 7. The yarn shown in FIG. 8 is a product obtained by passing through both the scrubbing device and fluid false twister in this order. 7

In FIG. 12, is shown an eccentric disc 25, moving friction means, which serves as a false twister. The shaft 26 is mounted eccentrically to the disc. The yarn running along the shaft intermittently and frictionally contact with the surface of the disc as the disc rotates. gaining an alternate twist in its length. The disc may be substituted for the fluid false twister for the purpose of practicing the invention.

FIG. 13 schematically and partially shows one type of jet loom for weaving the slub yarn as a weft. The slub yarn is supplied from a supply'package 27 through guide 28 and 29, tensor 30, guide 31, and a pair of feed rolls 32 and 33 to pool pipe 34. The yarn is then withdrawn from the pool pipe 34, and the yarn passes through a pair of nip members 35. The yarn then is jetted with water by the nozzle 36. The nip members intermittently nip the slub yarn in accordance with a jetting cycle.

When the multifllament yarn is overfed into the deflected stream flowing backwardly from the apex of the hood, the numerous filaments forming the yarn are separated in any number of groups which are simultaneously folded back on themselves with each group in an entanglement. It is found that an irregularity of intervals of the slubs results on the yarn from a cooperation between the yams overfeed and passage in adverse direction against the flow of the deflected stream of the gas. It is noted that such irregular characteristic is essential to make the resultant yarn applicable in the commercial field.

The phenomenon from which the formation of the slub is I achieved is not formulated, but it is our belief that there are various factors by which the formation of the slub is controlled, such as, for example, a pressure of the compressive gas, configuration or size of the hood, overfeed ratio of the yarn, and the like. We suppose that the most essential factor to acquire the irregular characteristic is the passage of the yarn through the deflected stream of the gas in countercurrent direction against the flow of the jet.

Various values in the undergoing specification have therefore been elected after extensive experiments.

Any type of hood will sufficiently be employed for the purpose of practicing the present invention, so far as desired deflection of the stream is obtained. It is. preferred that the inner surface of the hood, at least the surface in the vicinity of the apex, is smoothly curved to insure the stream an efficient flowing and deflection. It isalso found that the compressive gas is jetted in the chamber of the hood and the centerline of the jetted stream of gas is offset from the central, i.e. longitudinal axis of the hood.

Any kind ofgas may be used in practicing the invention, if it is harmless and the pressure of the jet is controlled in a range of from 0.5- KgJcm. under a guage pressure. This range is not severe and a latitude should be permitted in a somewhat lower range than 0.5 Kg./cm. In view of ready availability and lower cost, air is beneficially selected for the practice of the invention.

Although the overfeed length of the yarn is found applicable in the range of 05-50 percent relative to the withdraw, the range of about 2 percent is found beneficial.

As used herein, overfeed is defined as:

feed rate-withdrawal rate overfeed It will be obvious that the yarn may be supplied to the deflected stream either directly or otherwise through a jetting nozzle and one or more of a plurality of yarns may be used in doubled state to acquire a particular effect on the resultant yarn. In this practice, any one or more of them may be supplied separately from the other by passing through the jetting nozzle or not.

A false twisting has been found advantageous in combining with the procedure above described for the purpose of gaining a consolidation ofthe slubs.

As the false twister, a vortex stream of gas may be utilized to impart a false twist to the yarn after leaving the hood. By this, a greater tightness and consolidation can be attained as to the slub forming. The pressure ofthe vortex gas is regulated in the range of about 0.5-5 KgJcmF.

Any other type of false twister, such as friction disc, may be used for the same purpose.

By the false twist, cohesion between filaments is beneficially obtained, opposing an obstruction to a weaving trouble. It should be noted that the true twist which may have been imparted in the slub yarn will fall into the breakage as would defeat the purpose of weaving yarn.

In the following examples an d tables, the de gree of the stability of slubs is designated as d value (a low d value means a high stability), which is determined in the following manner.

A sample yarn of 20 centimeters length having one slub in its length was supported horizontally in a tension state by fixing at both ends. A weight of (deniers of monofilament X 0.01 grams was then suspended by one of a plurality of loops of the slub by means of hanger hook. After sufficiently allowing the loop to loose by the load of the weight, an amount of a downward shift exhibited by the weight was measured. The same tests were repeated 200 times as to the sample yarns of the same nature. From the obtained values, there was yielded an arithmetic mean value representing 2 value.

As shown in Table 1, several embodiments of the hood according to theinvention was used in the examples.

' TABLE 1 A Ellipse... .5 12 B d0 .5 15 0.. .6 20 D. d .0 15 E do .0 6

Note:

1. Type of hood 2. Cross-sectional shape at open end of hood 3. Length of maximum axis of the ellipse, centimeters 4. Length of minimum axis of the ellipse, centimeters EXAMPLES I TO 3 Examples 1 to 3 respectively were carried out to produce a slub yarn by using embodiments of the apparatus similar to the apparatus of FIG. 1. The operational conditions are shown in Table 2 and the results obtained are given in Table 3.

EXAMPLES 4 TO 9 Examples 4 to 9 respectively were carried out to produce slub yarn by using different embodiments of the apparatus,

each of which is substantially similar to the embodiment of FIG. 1 except that each is provided with a yarn scrubbing device 17.

EXAMPLES 10 T0 1 2 Examples 10 to 12 respectively were carried out to produce a slub yarn by using embodiments of the apparatus, each of which is substantially similar to the embodiment of FIG. 3.

EXAMPLES 13 TO 17 Examples 13 to 17 were respectively carried out to produce a slub yarn by using different embodiment of the apparatus, each of which is substantially similar to the embodiment shown in FIG. 9.

EXAMPLE l8 of I cen- TABLE 2. EXAMPLES OF PROf'Fm'e (OYUITIONS A B I) E F G H Example No.

l Polyethylene oxyhenzoate (150/48 208 200 L A 4 0. 5 .o... 206 200 1.0. .A 4 0.5 3. Polyethylene oxybenzoate (100/48) 240 200 1.0 A 4 0.5 4 Polyethylene oxybenzoate (150/48) 312 300 1. 5 C 4 0.5 5. .00. 303 300 5.0 C 4 0.5 6.. ....(lo 303 300 0.5 C 4 0.5 7 Nylon 6 (70211 208 200 1.2. B 3 0.5 0 208 200 1.2.. B 10 0.5 0 Polyethylene oxyhenzoate (70/36) 204 200 1. 5 A 4 0. 5 10.. Polyethylene oxybenzoate (100/48) 184 180 1.5 1.0 A 4 0. 5 ..do.... 184 180 1.5 0.5 A 4 0.5 184 180 1.5 4.5 A 4 0.5 13 Polyethylene terephthalate (150/48). 186 180 3.0 1. 5 A 4 1.0 14 do 200 180 3.0 1.5 A 4 1.0 15 Viscose rayon (600100). 150 150 3.0 2. 0 D 6 2. 0 16 Nylon 6 (70/24) 204 200 1. 5 1.0 E 2 0. 5 l7. Cellulose aeetate(150,'50) 204 200 1.5 0.5 A 2 0.5 8 Polyethylene oxybenzoate (150/48)... 210 200 1. 5 A 4 0. 5

Note: 1. A process for producing a slub yarn which includes the A. Type of yarn treated (total denier/filaments) steps of: B. Feed speed ofyam (meter per minute) 20 a. jetting a stream of compressive gas into a hood having a C. Withdrawal speed of yarn (meter per minute) hole at the apex thereof to deflect at the apex and to D. Pressure of compressive air used for deflected stream escape backwardly,

(Kg/cm?) b. feeding a multifilament yarn in the deflected stream of E. Pressure of compressive air used for vortex (Kg/ gas to fold back the filaments on themselves at the apex of F. Type of hood the hood, and 6. Distance from top end of nozzle to bottom of hood (mm c. withdrawing the yarn from the deflected stream of gas timeter) through the hole in the hood, at a rate at least 0.5 percent H. Distance from center of nozzle to central axis of hood less than the rate of feed, so that the yarn passes through 1. Center lntlS of nozzle used was in parallel with axis of the deflected stream of gas in a countercurrent direction hood to form slubs composed of filament loops consolidated 2. Nozzle was located on the maximum axis of the elliptical section ofthe hood in examples except Example 9 3. Nozzle was located on the minimum axis of the elliptical section of the hood in Example 9 into the yarn by filament entanglement. 2. The process as defined in claim 1 wherein the centerline of the jetted stream of gas is offset from the central axis of the hood.

TABLE 3.-CHARACTERIZATION PARAMETERS OF VARIOUS SLUB YARNS Example Slub characterization parameters 1 2 7 9 10 15 16 18 Average slub length, cm 3. 5 3. 0 3. 7 2.8 3. 3 4. 1 1.8 3. 6 slubs/100 meters 49 43 32 28 184 97 52 Longest slub in samples analyzed, em..- 8 9 11 4 9 14 6 10 Shortest slubs in samples analyzed, cm... 0. 5 0. 5 0. 5 0.2 O. 5 O. 5 0.2 0. 5 Average denier ratio of slub to base yarn 3.3 3. 4 4. 4 3. 6 2. 4 1. 8 2. 2 3. 7 Average interval length between two slubs, cm 208 238 322 370 227 54 104 196 Percentage of slub interval having a length greater than- (a) Average interval length 41 44 48 47 42 46 43 44 (b) 0.5 X average interval length. 69 64 66 61 67 72 76 67 (c) 0.2 X averageinterval length 83 87 78 82 85 81 92 79 (d) 1.5 X averageintervallength. 19 26 27 29 23 18 19 24 (e) 2.0 X average interval leugth 12 16 18 21 15 13 11 17 11 value, mm 17 13 19 8 3 6 7 4 EXAMPLE I) 3. The process as defined in claim 1 wherein the compressive as is 'etted into the chamber of the hood. The slub yarn obtamed by the process of Example 2 was g woven imo warp of polyethylene oxybenzoate yam (50 4. process of claim 1 wherezin the pressure of the comdeniers/36 filaments) having no slub, by using an embodiment presswe gas 15 at least of the water jet loom as shown in HQ 5 5 5. A process for producing a slub yarn which includes the Average denier of slubs in the slub yarn was about 510 stepshfi deniers a. etting a stream of compressive gas 1nto a hood having a The dimensional value of the water jet loom used and the hQle at the p thereof to deflect at the apex and to weaving conditions were as follows: escahe backwahdly I Inside diameter ofthe guides. 4 mm b. feedmg a multifilament yarn 1n the deflected stream of inside diameter ofwater nozzle; 20 mm gas to fold back the filaments on themselves at the apex of Tension between tenser and a pair of feed rolls: 0.01 g./dehoodihhd nier c. withdrawing the yarn from the deflected stream of gas Rotating Speed of the crank Shaft of the loom; 3 50 through the hole in the hood, at a rate of at least 0.5 per- Space between nip devices: 20 mm cent less than the rate of feed, so that the yarn passes wa density 120 yams/inch through the deflected stream of gas in a countercurrent wegdensity '7o yams/inch direction to form slubs composed of filament loops con- The woven fabric had an appearance similar to shantung wlldate? the yam by filamen? entanglement and fabric, on the surface of which there is projected no rough falshitwlstmg the yam after passmg through the hood to nap. Such effect is desirable for the commercial use and is ob- 7Q Stablhze the configuratpn' I tainable from th fact that the water absorbed in the yarn ena- The PromsS as defilled 5 Where!" the false bles the loops to adhere to the yarn when the yarn is nicked mg 15 Performed y P g through a Vorlex Ofa compresslve into shed during the weaving operation and to prevent the nap from ro'ectin on the surface of the resultant fabric. There 7. The rocess as defined in claim 5 wherein the false twiste 1 g P was hardl ex erienced an breaka e of the slub yarn durmg in is erformed b assin throu h a movln fr1ct1on means Y P y g g P y P g g g the weaving operation by using the yarn as a weft.

We claim:

in friction contact with the surface of said moving friction means.

232533 STATES LA'ELNL CERTIFICATE F CORRECTION Patent No. 3:59- :955 July 3: 97

Dated inventor) Shiro Fajita, Jusuke Ushiki, Nagao Nishizawa, SeiJi Okawa,

nunlo man It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F I j The name of the assignee is incorrectly stated as Nippon Rayon Co.Lt whereas the assignment records show a merger of Niiopon Rayon Co.Ltd. to Unitika Ltd.

Signed and sealed this 21st day of March 1972.

(SEAL) 1 Attest' EDWARD M.'FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

2. The process as defined in claim 1 wherein the centerline of the jetted stream of gas is offset from the central axis of the hood.
 3. The process as defined in claim 1 wherein the compressive gas is jetted into the chamber of the hood.
 4. A process of claim 1 wherein the pressure of the compressive gas is at least 0.5 kg./cm.2 .
 5. A process for producing a slub yarn which includes the steps of: a. jetting a stream of compressive gas into a hood having a hole at the apex thereof to deflect at the apex and to escape backwardly, b. feeding a multifilament yarn in the deflected stream of gas to fold back the filaments on themselves at the apex of the hood, and c. withdrawing the yarn from the deflected stream of gas through the hole in the hood, at a rate of at least 0.5 percent less than the rate of feed, so that the yarn passes through the deflected stream of gas in a countercurrent direction to form slubs composed of filament loops consolidated into the yarn by filament entanglement, and d. false-twisting the yarn After passing through the hood to stabilize the configuration.
 6. The process as defined in claim 5 wherein the false twisting is performed by passing through a vortex of a compressive gas.
 7. The process as defined in claim 5 wherein the false twisting is performed by passing through a moving friction means in friction contact with the surface of said moving friction means. 